Meet the famous Kurutoga pencil with rotating lead. The lead rotates slightly every time you press down, wearing it down evenly for a lead that is always smooth.   

To match the blue beauty, you can add erasable blue lead.

Why blue?  According to the legend of ancient cartoon art found in caves...  Alright.  That bit might be made up, but cartoonist have discovered that certain shades of blue don't show up in scans or photocopies.  Rough blue sketches can be inked over and converted to digital without an eraser in sight.